Wright, Charles Robert, author
New York, N.Y. Random House 1966,
Buku Teks
Wright, Charles Robert, author
Random House, 1975
Buku Teks
Wright, Charles Robert, author
Ramaja Karya, 1986
Buku Teks
Grindstaff, Carl F., author
Christopher Publishing House, 1981
Buku Teks
Foster, Lois E., author
Prentice-Hall, 1981
Buku Teks